Theoretical investigation for the reactions of hydrogen atom with dimethyl sulfide, ethyl methyl sulfide: Mechanism and kinetics properties

An exhaustive and theoretical analysis for the CH3SCH3 + H and CH3CH2SCH3 + H reactions has been examined using quantum chemistry theory over the temperature range of 300-1500 K. The potential energy surface was obtained by the CCSD(T)/CBS//M06-2X/cc-pVTZ theory. The overall rate coefficients have been analyzed and the energetics and reaction enthalpies were also calculated. Three kinds of reaction channels have been analyzed: hydrogen abstraction, CH3S-transfer and CH3-transfer channels. In the CH3SCH3 + H reaction, the CH3S-transfer channel forming CH3SH + CH3 center dot is more predominant. For the CH3CH2SCH3 + H reaction, the channel forming CH3SH + CH3CH2 center dot is kinetically more favorable compared to the other channels at low temperature region.